Labor migration is a major contributor to fueling the global AIDS epidemic and also the movement of HIV across country borders and populations. Migrants who inject drugs while in a host country are at especially high risk. Tajikistan, a small country in Central Asia, exports more than a million Tajiks annually, many of whom inject drugs, to work outside of their own country. Our earlier research on Tajik labor migrants in Moscow showed them to be at alarmingly high normative and behavioral risk for HIV due to risky drug use, needle sharing, alcohol consumption, and unsafe sex with casual and paid sex partners. To help curb transmission in this vulnerable population, the proposed study will develop the Migrants' Approached Self-Learning Intervention in HIV/AIDS for Tajiks (MASLIHAT) prevention model. The model recruits and trains current and former Tajik migrant IDUs as peer educators in delivering the intervention to IDUs and others in their social networks while simultaneously reducing their own risk. The MASLIHAT Intervention and our research efforts build synergistically on 3 theoretical models: social-cognitive-behavioral theory, Social network theory and Yang's Theory of Migration. The model itself culturally adapts the successful SHIELD model, which is a CDC- designated evidence-based best practice intervention in the U.S., for use with migrant IDUs. AIM 1 will develop the MASLIHAT Intervention to reduce risky drug, alcohol, and sexual behavior among Tajik male labor migrants in Moscow who inject drugs. AIM 2 will pilot test the MASLIHAT Intervention with 30 Tajik male migrant peer educators who are former or current IDUs and 60 of their Tajik male IDU social network members. We will deliver 4 cycles of MASLIHAT 5- session trainings sequentially with 7 to 10 Peer educators per cycle (30 peer educators total; each cycle is held over a 3 week period). The peer educators, in turn, will share what they learned with others in their social networks, including the 2 network members who are enrolled in the study. Both the 30 peer educators and 60 network members will be interviewed at baseline, 3 months, and at 6 months. We will conduct repeated measures linear and logistic regressions using mixed effect models with random person intercepts to test: (1) if peer educators change their HIV norms and behavior due to active participation in MASLIHAT and (2) if network members change their HIV norms and behavior as the result of interaction with the peer educators. Social network analysis will assess the intervention's penetration into IDU networks by key characteristics (structure, nodes, density, ties, mixing). By transforming their own HIV norms and behavior, and encouraging others at risk to do so as well, migrant peer educators can initiate positive changes at the individual and social network levels in both their host country and also their home country when they return. The impact of the proposed study lies in the development of a much needed intervention for clinical trial testing that reduces HIV transmission among Migrant IDUs within and across country borders.